Immunosensors environmental applications

Immunosensors for clinical and environmental applications based on electropolymerized films analysis of cholera toxin and hepatitis C virus antibodies in water and serum... 

S. Laschi and M. Mascini, Disposable electrochemical immunosensor for environmental applications, Ann. Chim., 92 (2002) 425-433. 

Several protocols with potential biomedical and environmental application have been developed. Table 38.2 summarises information of some typical electrochemical immunosensors using AuNPs tags. 

The development of electrochemical genosensors and immunosen-sors based on labelling with NPs has registered an important growth, principally for clinical and environmental applications. The electrochemical detection of NP labels in affinity biosensors using stripping methods allows the detailed study of DNA hybridisation as well as immunoreactions with interest in genosensor or immunosensor applications. 

Among this variety of immunosensor systems, two optical immunosensor devices for environmental applications RIANA and AWACSS are especially noteworthy. These immunosensors are based on solidphase fluoro-immunoassays combined with an optical transducer chip chemically modified with an analyte derivate. The RIANA immunosensor was applied successfully in a variety of environmental applications (Mallat et al., 1999 Rodriguez-Mozaz et al., 2004b). The other new analytical system AWACSS has... 

The main practical environmental application of SPR has been as an immunosensor for the detection of phytosanitary products (Mullet, 2000). Recently, SPR immunodetection of 2,4D (Kim et al., 2007), DDT (Mauriz et al., 2006a, 2007), chlorpyrifos and carbaryl pesticides (Mauriz et al., 2006b) was found ten times more sensitive than ELISA methods, with detection limits in the ppt range, and an analysis time of less than 20 min. 

All these advantages have made microfluidic immunoassays platforms as emergent, powerful option for the analysis of a broad variety of analytes in different fields. Although still it is in its infancy, microfluidic immunosensors reveal as very promising tool in environmental applications. For supplementary information, the reader is guided to excellent review articles. ° ° ... 

O.A. Sadik and J.M. van Emon, Applications of electrochemical immunosensors to environmental monitoring. Biosens. Bioelectron. 11, i-xi (1996). 

Immunosensors promise to become principal players in chemical, diagnostic, and environmental analyses by the latter 1990s. Given the practical limits of immunosensors (low ppb or ng/mL to mid-pptr or pg/mL) and their portability, the primary application is expected to be as rapid screening devices in noncentralized clinical laboratories, in intensive care facilities, and as bedside monitors, in physicians offices, and in environmental and industrial settings (49—52). Industrial applications for immunosensors will also include use as the basis for automated on-line or flow-injection analysis systems to analyze and control pharmaceutical, food, and chemical processing lines (53). Immunosensors are not expected to replace laboratory-based immunoassays, but to open up new applications for immunoassay-based technology. 

Although the spectrum of NPs for labelling applications is relatively broad, this chapter discusses only the application of gold NPs (AuNPs) in electrochemical genosensors and immunosensors and some of the trends in their use for environmental and biomedical diagnostics between other application fields. 

Actually, special attention is paid in the application of biosensors in environmental analysis. The high cost and slow turnaround times typically associated with the measurement of regulated pollutants clearly indicates a need for environmental screening and monitoring methods that are fast, portable and cost-effective. To meet this need, a variety of field analytical methods have been introduced. Because of their unique characteristics, however, technologies such as DNA sensors and immunosensors based on AuNPs might be exploited to fill specific niche applications in the environmental monitoring area. 

The analysis of trace substances in environmental science, pharmaceutical and food industries is a challenge since many of these applications demand a continuous monitoring mode. The use of immunosensors based on AuNPs in these applications should also be appropriate. Although there are many recent developments in the immunosensor field, which have potential impacts [36], nevertheless there are few papers concerning environmental analysis with electrochemical detection based on AuNPs. The application of some developed clinical immunosensors can also be extended to the environmental field. 

Marco, M.-P. and D. Barcelo. 2000. Immunosensors for environmental analysis. In D. Barcelo (ed.), Sample Handling and Trace Analysis of Pollutants Techniques, Applications and Quality Assurance, pp. 1075-1103. Amsterdam Elsevier. 

The application of optical immunosensors for environmental monitoring started some years ago. The use of sensors for the measurement of pollutants is a viable alternative in environmental control where it is important to develop sensors of small size, that are reliable, sensitive and selective, for operation in situ and produced by a low cost technology. Several applications have been reported mainly applied to pesticide detection (herbicides, biocides, etc.). The SPR technology has been applied to many environmental problems, mainly for the detection of pollutants in the aquatic environment, such as... 

Despite their high cost and the long process involved in their development, immunochemical techniques may soon have broad applicability in the environmental field. Antibody production is the key step of any immunochemical technique. Immunosensors yield the best results for pesticides determination104 in terms of both accuracy and reliability. The most reliable immunosensors are piezoelectric. They assure a good sensitivity and limit of detection.105 The main problem for piezoelectric immunosensors utilization for water analysis is their low sensitivity, which results in a decrease in the S/N ratio because of the impurities present in water (from matrix or other sources). 

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